Bound on dissipative effects from semileptonic neutral B-meson decays

The semileptonic decay asymmetry ${\mathcal{A}}_{\mathrm{\Delta }m}$ is studied within the open quantum systems approach to the physics of the neutral meson $B^0$-$\overline{B^0}$ system: this extended treatment takes into account possible non-standard, dissipative effects induced by the presence of an external environment. A bound on these effects is provided through the analysis of available experimental data from the Belle Collaboration.